Enhanced write performance of a 64 Mb phase-change random access memory

A 1.8 V 64 Mb phase-change RAM with improved write performance is fabricated in a 0.12 /spl mu/m CMOS technology. The improvement of RESET and SET distributions is based on cell current regulation and multiple step-down pulse generators. The read access time and SET-write time are 68 ns and 180 ns respectively.